The present disclosure relates generally to vehicle object detection systems and, more particularly, to a method and system for vehicle impact assessment using driver braking estimation.
One of the more recent systems to be developed in the automotive industry is the forward collision warning (FCW) system. An FCW system is intended to mitigate and/or eliminate frontal impacts by generating a timely warning to the driver to take an evasive action. Typically, a vehicle is configured with a sensor (or sensors) that is capable of detecting objects in the frontal area of the vehicle. The sensor not only detects the presence of an object, but also provides some quantitative information about the object such as range, range rate, and azimuth position of the object. Additional information related to the object (e.g., a lead vehicle in many instances) may include relative acceleration, the size of the object, the dimensions of the object, the direction of movement of the object, etc. Generally speaking, two main technologies are most prevalent in gathering such object information: (1) laser technology; and (2) radar technology.
In addition to the gathered object data, an FCW system also typically incorporates a threat assessment algorithm, which evaluates the incoming data, analyzes the particular situation, and then determines if there is any imminent threat of impacting an object in the frontal area of the vehicle. Many of these algorithms are based on parameters such as “time to impact”, “time headway”, or perhaps basic vehicle kinematics. In any case, the output of the algorithm will determine if the FCW system will cause a warning to be issued to the driver.
False alarms generated from a FCW system are a source of nuisance to the driver. Such false alarms may result from erroneous information picked up from the sensor(s), or may be generated as the result of shortcomings in the threat assessment algorithm itself. In the latter case, the false alarm is a “too early” warning, which can annoy the driver. On the other hand, a missed detection results from a situation where an impact warning was supposed to be issued by the FCW system, but was not, due to erroneous sensor information or due to the threat assessment algorithm. The latter is in the form of a “too late” warning, or even no warning at all, such that the overall effectiveness of the system is compromised or diminished. However, algorithms based only on the above mentioned parameters tend to exhibit these characteristics.